How our microbiome develops and what role the microbes in the gut and vagina play for our health, especially during pregnancy, is my recurring theme here at FP. To read some of my previous posts on the matter, click here.

My daughter got married this last summer and it sparked a thought about a very interesting question. Could it be, that microbes also affect which people we are attracted to and which sex partners we choose? 

Can we use scent to detect a suitable partner?

The bacteria on our skin contribute to our body odor, which is an important part of how we choose a partner. For example, the bacteria transform the oil we have on our skin into a very unique blend of fatty acids and other substances that give us a distinctive scent, our very own signature. Imagine the process as a lure that the bacteria produce to gain access to another human body host to colonize. After all, sex can be quite sweaty and messy, an almost perfect set-up for bacterial transmission.

In addition to this, our immune system plays an important role in how we perceive the scent of other people. Our immune response genes become yet another personal scent signature that has been trained by bacteria from an early age. There are studies that show that we unconsciously choose a partner with immune response genes that are different from our own.

Bacteria communicate with each other through different signaling substances, some of which are the same hormones that cells in us humans produce, such as oxytocin and serotonin. They contribute to our love life by regulating our moods and are needed for our well-being and sense of closeness.

In a controlled study of 21 couples who were intensely kissed, a research group from Amsterdam showed that about 8 million bacteria were exchanged per second. One person from each couple had to drink a probiotic yogurt before kissing, and the researchers measured the probiotic bacteria in the saliva of the partner. In addition, the study showed that couples who kiss each other often have a bacterial flora in their mouths that is more similar to each other than that found in the mouth of other people.

How should we deal with the invasion of microbes in our love life?

First, don’t try to hide your own scent signature by using too much perfume or cologne. Secondly, you may not need to use such large amounts of soap as what it common nor shower too frequently (this also saves on the environment). Above all, make sure to nurture your bacterial flora on and in your body through a varied diet that contains a lot of fiber, a lifestyle of regular physical activity and some time in nature. It helps you maintain radiant skin and an irresistible scent of health and attraction. Instead of dating apps, you just need to get out in the crowd and trust your nose!

There is very little we know today about the role of bacterial flora in women’s health and the correlating potential to give birth to healthy children. But we at the Center for Translational Microbiome Research have started several studies to find out. The SweMaMi study has now received samples from 1000 mothers and children, 1000 pregnant women are already present and will send more samples to us but 500 are still missing. So I can’t help but ask, are you pregnant? and are you interested in participating? 

Watercolor: Ina Schuppe Koistinen

This is a guest post. The opinions expressed are the writer’s own.